1. Technical Field
The present invention relates to an electro component package.
2. Description of the Related Art
With high-performance of digital products, the frequency of a signal transmitted and received between semiconductor devices is now becoming higher. Such a signal is transmitted through wiring formed on a substrate. Transmission quality of the signal is determined according to the characteristic of the wiring. It the transmission quality is bad, a maximum bandwidth of a signal which can be transmitted is limited.
In an electro component package according to a conventional technology, communication between a CPU chip and a memory chip is, as shown in FIG. 1, carried out through a path in the order of a bump of a CPU chip 1, wiring of a CPU package substrate 3, a solder ball, main board wiring, a solder ball, wiring of a memory package substrate 4 and a bump of a memory chip 2.
Such discontinuous points generate reflection during the transmission of a radio frequency signal and obstruct the transmission of the radio frequency signal. In order to get over the transmission obstruction caused by the reflection, a semiconductor circuit should consume more electric power.
The radio frequency signal should be regarded as a wave instead of a simple electrical signal. From the viewpoint of the transmission line of the wave, such a discontinuous environment limits transmission speed of the radio frequency signal.
While a method of locally increasing the output of a driver in a chip so as to overcome the disadvantage, a system is increasingly consuming more electric power.
An electro component package having a structure that has been improved better than that of FIG. 1 is provided in FIG. 2. The electro component package shown in FIG. 2 transmits a signal from the CPU package substrate 3 to the memory package substrate 4 by use of a substrate separated from the main board 5. However, the structure of FIG. 2 also has a limit in minimizing reflection generated during the transmission of the radio frequency signal.